Who was eradicated in "Ein Dor"?
Rashi: I do not know if this was via Gid'on or Barak.
Radak #1: This refers to Midyan, even though it is not mentioned in Sefer Shoftim.
Radak #2: This refers to Sisera. Ein Dor is in Menasheh's portion, with Tanach and Mei Megido mentioned in Shiras Devorah (Shoftim 5:19).
Malbim: Yavin Melech Chatzor ruled also over Ein Dor (Yehoshua 11:2, 10). Yisrael did not dispossess it; Kena'anim lived there (ibid., 17:12). When they fled from Barak, they were destroyed there, and were like excrement on the ground.
What is "Domen"?
Rashi: It is scattered excrement, like Yonason translated 1 .
Radak: It is what is trampled on, like excrement in the wasteheap.
Yonason did not translate Kesuvim (Megilah 3a). Surely Rashi refers to Targum Yonasan on Nevi'im, e.g. Melachim II, 9:37. (PF)